Tesla filed a lawsuit in California this week alleging that a former employee stole source code for its Autopilot self-driving technology before leaving the company to join a Chinese startup. Guangzhi Cao has worked for Xiaopeng Motors (sometimes simplified to Xpeng) since January, according to his LinkedIn profile, serving as "head of perception" (whatever that means). According to the lawsuit, Tesla alleges that Cao copied more than 300,000 files before leaving Tesla.